Ruler pen



FIG. 1 is a perspective view of ruler pen showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is right side elevational view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is a perspective view thereof in an exploded condition; and,

FIG. 9 is a second perspective view of FIG. 1, the structure depicted by means of broken lines being shown for illustrative purposes only and forming no part of the claimed design. 

The ornamental design for ruler pen, as shown and described. 